The overall objective of this proposed research is to determine the mechanisms of action of the adenovirus EIA proteins in transcription induction and cellular transformation. The specific aims are: (1) to determine if the EIA proteins are required continuously for induction of transcription and cellular transformation, (2) to determine which of the EIA proteins is required for cellular immortalization, and to determine which cellular RNAS are induced by EIA in immortalized cells, (3) to study whether there is a functional interaction between the two EIA proteins, (4) to determine whether other genes involved in the establishment of cellular transformation also have transcription inducing properties, (5) to correlate the enhancer sequences found in EIA with tissue specific expression of viral genes, and (6) to develop an in vitro functional assay for the EIA proteins. These studies will be important in attempting to determine the mechanism of action of the EIA proteins. To determine this mechanism it will ultimately be necessary to purify these proteins, and develop in vitro functional assays of their activity. It is likely that proteins from other DNA and RNA tumor viruses will have similar mechanisms of transcription induction and transformation. Thus by studying the mechanism of action of the EIA proteins, a more general understanding of eukaryotic transcriptional regulation and cellular transformation will be obtained.